ORGANIC WEED MANAGEMENT IN MAIZE (Zea mays L.) THROUGH INTEGRATION OF ALLELOPATHIC CROP RESIDUES

Weed suppression is one of the several benefits associated with application of crop residues as mulch in field crops.Nonetheless, the crop residues on the soil surface contribute physically towards weed suppressive effect, yet the chemical effect of phytotoxins released from decomposing residues alsoimparts significantly for weed control. A field experiment aimed at establishing the weed suppression potential of mixture of cropresidues and their effects on maize yield was conducted.Residues of sorghum (Sorghum bicolor L.), sunflower (Helianthusannuus L.), rice (Oryza sativa L.) and brassica (Brassicacampestris L.) in various combinations were soil incorporated at 4.5 and 6 t ha-1. Results revealed that a combination of sorghum+ sunflower + brassica residues at 6 t ha-1 provided 90% suppression in density and dry weight of horse purslane(Trianthema potrtulacastrum L.) and purple nutsedge (Cyperusrotundus L.) as compared with control (no residue). This treatment also accounted for maximum maize grain yield and net benefits. For better management of natural resources and to decrease environmental pollution, soil incorporation of cropresidues may serve as an important weed management tool inmaize fields.